Cal. Gov. Code § 66499.58

All surveys and the field notes thereof made by any engineer or surveyor, under the provisions of this division, or in surveying officially any lots or parcels of land in any city, town or county for the purposes of any map under this division, shall be filed in the office of the surveyor or engineer, as the case may be, and shall become a part of the public records of the city, town or county.